In the translation of the rotary motion of a motor to linear reciprocal motion of a piston, inertial and frictional forces are encountered that limit the response time of the valve during motor start and stop. It is desirable to have a rotary valve that has a lightweight rotatable cavitated disk to reduce inertial effects for rapid stops and starts and for translating the rotary action of the shaft of a motor over a broad range of frequencies into the reciprocating action of a piston with minimum loss of energy. A lightweight rotary cavitated disk coupled directly to the motor shaft, dynamically balanced, and rotating on an air bearing or air cushion substantially reduces inertial effects and frictional losses and permits the valve to accelerate to the rated motor speed in milliseconds after start and accordingly achieve in phase reciprocating motion of a piston with the same frequency as the motor. It is also desirable that the rotary valve efficiently distribute fluid medium and communicate with the cylinder containing the piston for both the intake and exhaust of fluid by having one pressure port for supplying fluid under pressure to the cavitated disk, a first and second cylinder conduit communicating with the pressure port, and a first and second exhaust ports that alternately communicate with cylinder ports such that the valve can be operated in two-way, three-way, or four-way configurations by connecting fluid lines only to the ports needed for the selected operation.
It is therefore an object of the present invention to provide a rotary valve device to translate the rotation of a motor shaft into the reciprocating motion of a piston with minimum loss of energy.
A more specific object of this invention is to provide a lightweight rotary cavitated disk which is directly coupled to a motor shaft and rotates on an air bearing where the bottom surface of the cavitated disk is located at a pre-determined distance from the planar surface of a manifold where a fluid medium under pressure is continuously delivered to the manifold and distributed by the cavitated disk for cyclically driving a piston and exhausting the fluid medium to the atmosphere.